Twin T circuit wanted
in [Design]
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From: Jim Thompson on 8 Jun 2010 20:27 On Tue, 08 Jun 2010 17:13:17 -0700, John Larkin <jjlarkin(a)highNOTlandTHIStechnologyPART.com> wrote: >On Tue, 8 Jun 2010 16:04:33 -0700 (PDT), dagmargoodboat(a)yahoo.com >wrote: > >>On Jun 8, 5:09�pm, John Larkin >><jjlar...(a)highNOTlandTHIStechnologyPART.com> wrote: >>> On Tue, 8 Jun 2010 14:53:04 -0700 (PDT), dagmargoodb...(a)yahoo.com >>> wrote: >>> >>> >>> >>> >On Jun 8, 2:09�pm, John Larkin >>> ><jjlar...(a)highNOTlandTHIStechnologyPART.com> wrote: >>> >> On Tue, 8 Jun 2010 10:00:55 -0700 (PDT), dagmargoodb...(a)yahoo.com >>> >> wrote: >>> >>> >> >On Jun 8, 10:31 am, Jim Thompson <To-Email-Use-The-Envelope-I...(a)On-My- >>> >> >Web-Site.com> wrote: >>> >> >> On Mon, 07 Jun 2010 20:33:23 -0700, John Larkin<jjlar...(a)highNOTlandTHIStechnologyPART.com> wrote: >>> >>> >> >> [snip] >>> >>> >> >> >This is kind of a cute circuit. I first designed it when I needed a >>> >> >> >very frequency and amplitude-stable sine wave to drive a Talyvel >>> >> >> >LVDT-like inclinometer, part of the Boresight Alignment Kit for the >>> >> >> >C5A. We had to measure level to arc-seconds of accuracy. >>> >>> >> >> >It's a transformer with a resonant tank in the collector and a >>> >> >> >positive feedback drive winding into the emitter. The emitter feedback >>> >> >> >is just a couple of tenths of a volt p-p. >>> >>> >> >> [snip] >>> >>> >> >> "designed"?? >>> >>> >> >> Quite _exactly_ like you'd find in common AM radios as the LO, once >>> >> >> transistors came upon the scene.... >>> >>> >> >>http://www.electronics-tutorials.com/receivers/rec-basic-fig1.gif >>> >>> >> >Cute, and familiar, yes, but that one doesn't have John's c-b >>> >> >conduction agc mechanism. �That's a pretty neat feature--have you seen >>> >> >it elsewhere? >>> >>> >> He has a pretty inexact definition of "_exactly_" >>> >>> >> It seems to mean "not very similar at all." >>> >>> >Easy boys. �I've designed stuff myself only to find others had beat me >>> >to it, and I conversely invented a really neat frequency multiplier >>> >which Wenzel and a few others later came up with too. �Mine was in >>> >mass production years before, but as far as they know they invented >>> >it. >>> >>> I never claimed that nobody had done this before; how could I know >>> that? I do claim that I hadn't seen it done before, nor since. And >>> it's cute. Who invented it isn't important; cute is. >>> >>> The old radio thing that JT linked to is nothing like it. It uses a >>> lot more parts and has classic 3-resistor class A biasing, among other >>> differences. >> >>Yeah yeah, we all get that. The circuits speak for themselves. No >>need to poke a stick at Jim--he's a good 'ol grizzly bar, just >>grouchy. The whole country's grouchy, the people ill-at ease. Such >>are the times. > >Not me. > >I recently read two articles about getting older: > >1. Unless you have dementia, brainpower tends to increase with age. >Exercizing your brain, like designing electronics, keeps it healthy. > >2. Personal happiness increases up to age 18, declines until about 50, >then increases pretty much for the rest of life after that. > >John I'm not grouchy... just a perfectionist. And I've been a happy camper all my life ;-) ...Jim Thompson -- | James E.Thompson, CTO | mens | | Analog Innovations, Inc. | et | | Analog/Mixed-Signal ASIC's and Discrete Systems | manus | | Phoenix, Arizona 85048 Skype: Contacts Only | | | Voice:(480)460-2350 Fax: Available upon request | Brass Rat | | E-mail Icon at http://www.analog-innovations.com | 1962 | The only thing bipartisan in this country is hypocrisy
From: George Herold on 8 Jun 2010 22:13 On Jun 8, 5:34 pm, default <defa...(a)defaulter.net> wrote: > On Tue, 08 Jun 2010 13:47:58 -0700, Jim Thompson > > <To-Email-Use-The-Envelope-I...(a)On-My-Web-Site.com> wrote: > > Sorry guys. > > I had no idea. I was just looking for a lazy shortcut, > > but to quote some western I saw a long time ago: > > "Why, Oh Why, Must there bee all this fight'n and kill'n?" (with a > Southern twang) > > Philosophically, "Everyone you meet can teach you something." No one > knows everything. The active is learning the passive is teaching. Well default, Though 'default' is not much of a name, I tend to agree with you. I only learn by making mistakes, and if you've stopped making mistakes.... well then you've stopped learning. (Good thing for me, as I can make mistakes faster than....) George H. > > Suffer the fools - they will always know something you haven't > learned. It isn't a contest, we all become fertilizer for another > generation. > > and preaching is easy if you have no skin in the game, mea culpa - so > have at it. > --
From: John Fields on 9 Jun 2010 11:57 On Tue, 08 Jun 2010 15:09:51 -0700, John Larkin <jjlarkin(a)highNOTlandTHIStechnologyPART.com> wrote: >If I claimed that there was nitrogen in the air, he and >JF would hack a Spice simulation and prove me wrong. Hell, if those >old hens ever did come up with sound generator circuits, one would >make pecking noises and the other would go "cluck." > >(How's that, rantwise?) --- About typical for a banty rooster who thinks that his crowing is what makes the sun rise.
From: John Fields on 9 Jun 2010 12:31 On Tue, 08 Jun 2010 15:09:51 -0700, John Larkin <jjlarkin(a)highNOTlandTHIStechnologyPART.com> wrote: >If I claimed that there was nitrogen in the air, he and >JF would hack a Spice simulation and prove me wrong. --- You're being absurd, as usual, but it seems you lucked out this time and your oscillator works in LTspice. Version 4 SHEET 1 880 680 WIRE -384 48 -592 48 WIRE -320 48 -384 48 WIRE -128 48 -224 48 WIRE 16 48 -128 48 WIRE 144 48 16 48 WIRE 240 48 144 48 WIRE 144 64 144 48 WIRE 240 64 240 48 WIRE -384 96 -384 48 WIRE 16 96 16 48 WIRE -448 144 -496 144 WIRE 144 160 144 128 WIRE 240 160 240 144 WIRE 240 160 144 160 WIRE -496 176 -496 144 WIRE -592 192 -592 48 WIRE -272 192 -272 112 WIRE -272 192 -384 192 WIRE 144 192 144 160 WIRE -128 208 -128 48 WIRE 16 240 16 176 WIRE 80 240 16 240 WIRE -384 272 -384 192 WIRE -272 272 -272 192 WIRE -496 288 -496 256 WIRE 16 304 16 240 WIRE 144 320 144 288 WIRE 240 320 144 320 WIRE 144 336 144 320 WIRE 240 336 240 320 WIRE -592 432 -592 272 WIRE -496 432 -496 368 WIRE -496 432 -592 432 WIRE -384 432 -384 352 WIRE -384 432 -496 432 WIRE -272 432 -272 336 WIRE -272 432 -384 432 WIRE -128 432 -128 272 WIRE -128 432 -272 432 WIRE 16 432 16 368 WIRE 16 432 -128 432 WIRE 144 432 144 416 WIRE 144 432 16 432 WIRE 240 432 240 416 WIRE 240 432 144 432 WIRE -592 496 -592 432 FLAG -592 496 0 SYMBOL ind2 224 48 R0 SYMATTR InstName L1 SYMATTR Value 10e-3 SYMATTR Type ind SYMBOL ind2 224 432 M180 WINDOW 0 36 80 Left 0 WINDOW 3 36 40 Left 0 SYMATTR InstName L2 SYMATTR Value 250e-6 SYMATTR Type ind SYMATTR SpiceLine Rser=.01 SYMBOL npn 80 192 R0 SYMATTR InstName Q1 SYMATTR Value 2N3904 SYMBOL res 0 80 R0 SYMATTR InstName R1 SYMATTR Value 100k SYMBOL cap 128 64 R0 SYMATTR InstName C1 SYMATTR Value 1e-6 SYMBOL voltage -592 176 R0 WINDOW 123 0 0 Left 0 WINDOW 39 0 0 Left 0 WINDOW 3 24 104 Invisible 0 SYMATTR Value 5 SYMATTR InstName V2 SYMBOL pnp -448 192 M180 SYMATTR InstName Q3 SYMATTR Value 2N4403 SYMBOL voltage -496 272 R0 WINDOW 123 0 0 Left 0 WINDOW 39 0 0 Left 0 WINDOW 3 24 104 Invisible 0 SYMATTR Value PULSE(5 0 0 1e-6 1e-6 .01) SYMATTR InstName V1 SYMBOL npn -320 112 R270 SYMATTR InstName Q2 SYMATTR Value 2N3904 SYMBOL cap -288 272 R0 SYMATTR InstName C4 SYMATTR Value 1e-6 SYMBOL res -400 256 R0 SYMATTR InstName R2 SYMATTR Value 1000 SYMBOL res -512 160 R0 SYMATTR InstName R3 SYMATTR Value 1000 SYMBOL cap 0 304 R0 SYMATTR InstName C2 SYMATTR Value 1e-8 SYMBOL res 128 320 R0 SYMATTR InstName R4 SYMATTR Value 1000 SYMBOL cap -144 208 R0 SYMATTR InstName C3 SYMATTR Value .1e-6 TEXT 160 184 Left 0 !K1 L1 L2 1 TEXT -576 464 Left 0 !.tran .5
From: John Larkin on 9 Jun 2010 13:30
On Wed, 09 Jun 2010 11:31:31 -0500, John Fields <jfields(a)austininstruments.com> wrote: >On Tue, 08 Jun 2010 15:09:51 -0700, John Larkin ><jjlarkin(a)highNOTlandTHIStechnologyPART.com> wrote: > >>If I claimed that there was nitrogen in the air, he and >>JF would hack a Spice simulation and prove me wrong. > >--- >You're being absurd, as usual, but it seems you lucked out this time >and your oscillator works in LTspice. > > Since we manufactured and sold lots of them before Spice was available, and they worked just fine, the luck is on Spice's part. Or yours. This will shock the kiddies, but it *is* possible to design circuits without using Spice. Usually it's faster and better. John |